AS 1884:2021 Floor coverings – Resilient sheet and tiles – Installation practices.
Section 3 Subfloors and underlays
3.1 Concrete subfloors
3.1.1 Construction
The surface of concrete subfloors shall be structurally sound to the building design specification and in accordance with building best practice.
NOTE AS 3600 is not an appropriate Standard for installation of resilient finishes as its specified tolerances for smoothness and planeness are too broad in scope.
3.1.2 Dryness
Before subfloor preparation is performed and a floor covering is laid on a concrete subfloor the dryness of the concrete shall be determined as described in Appendix A.
3.1.3 Surface pH
Before subfloor preparation is performed and a floor covering is laid on a concrete subfloor the concrete surface pH shall be determined as described in Appendix C.
3.1.4 Surface quality
The surface of a concrete subfloor shall be thoroughly checked for the following:
(a) Planeness — Refer to manufacturer’s planeness instructions. Where no manufacturer’s instructions are supplied, and a straightedge 2 000 mm long is placed at rest at any two points over a 2 000 mm distance, no part of the surface shall be more than 4 mm below the straightedge.
(b) Abrupt deviation tolerance— Where a straightedge 150 mm long is placed at any position at rest at two points on the surface, no abrupt surface deviation shall be more than 0.5 mm below the straightedge.
(c) Smoothness — The surface shall be regular with no holes, lumps or sudden rise or fall and with homogenous appearance.
(d) Soundness — The surface shall be without cracks, crazing, dusting, rain damage, spalling, efflorescence or blistering.
3.1.5 Surface preparation
Where subfloor repairs form part of the resilient installation contract, all grooves, holes and other concave imperfections shall be filled with a suitable cementitious material. Any ridges or protrusions likely to impair the subfloor surface shall be removed by mechanical means to achieve the required surface quality, see Clause 3.1.4. Any filling or levelling materials used shall be allowed to dry and cure before floor coverings are laid.
Mechanical preparation equipment shall be fitted with effective dust collection devices suitable to capture silica dust, see Clause 4.3. The prepared floor shall be vacuumed only and not swept.
Where a subfloor is so rough or uneven that it is unsuitable for the direct application of the resilient covering, corrective action should be taken (e.g. steel-trowelled underlayment).
Before laying operations begin, the following shall be removed from the subfloor by mechanical means, where present:
(a) Materials such as grease, oil or paint.AS 1884 pdf download.